Process of dyeing hair with 5, 6-dihydroxyindole



PROCESS OF DYEING WITH 5,6-DIHYDROXYINDOLE No Drawing. Application January 27, 1958 Serial No. 711,180 1 Claims priority, application France February 2, V1957 2 claims. 0. s-'-11 This invention relates to methods and compositions for dyeing hair, particularly human hair, and like materials. In our application No. 599,893 filed July 25, 1956, and

. now abandoned, we have described a process for dyeing hair and like fibers which consists essentially in (a) preparing an aqueous solution adjusted to an alkaline pH, containing 5:6-dihydroxy-indole and a reactant consisting of ammonia, an amine, an ammonium salt or an amine salt,

(b) applying this solution to the hair or similar material to be dyed and rinsing the latter after a period of contact varying in accordance with thedesired shade. In this way, relatively light shades ranging from light ash-blond to dark ash-blond are obtained for a standard period of contact of the order of from 20 to 30 minutes at room temperature, which period may. be reduced by slight heating, for example, in the case of hair-dyeing, by means of a dry heat hood or a steam hood. It is furthermore possible, in accordance with the method of the aforesaid application, to obtain a more rapid development of the shade by adding to the dyeing solution, at the time of application, an oxidizing agent, such assodium bromate, a persalt such as sodium perborate or ammonium persulphate, or simply hydrogen peroxide. There is to be noted that where an oxidizing agent is used it is necessary to make a wellbalanced choice of the quantity added, a minimum quantity being necessary for a sufficiently rapid formation of the colored pigments, while anexcess 'of thisagent' has the effect of more or less destroying said colored pigments intermediately formed and thus of reducing the depth of the. final shade. -As indicated in said application, it is possible to obtain dark shades closely comparable to the natural shades of the hair by operating in two steps, i.e. by first treatin'g'thehair withan alkaline solution of 5 :6- dihydfoxy-indoleat room temperaturefor 15 to 30 minutes and then, after-rinsing with water, applying to the hair afsolution of an oxidizing catalyst.

it is an' object of the present invention to provide a process for the dyeing of hair and likefibers by means of 5 :6-dihydroxy-indole while still operating in two steps, wherein the 5:6-dihydroxy-indole, solution applied in the first step, instead of being alkaline is either acid or neutral.

A'ccordingto the present invention a process for dyeing live hair and like materials consists essentially in impregnating the hair or like material at room temperature.

with an aqueous solution of 5:6-dihydr oxy-indole having a pH- value of at most. 7, allowing the impregnation to proceed for, about 5 to 60 minutes, blotting ofi the excess solution, and developing the shade in situ by applying an aqueous solution capable of inducing oxidationand/ or polymerization of 5: 6-dihydroxy-indole, the pH-value of which shouldbe adjusted in accordance with the specific oxidizingagent to be used. e V

The pH-value of the aqueous 5:6-dihydroxy-indole solution to be applied in a first step for carrying out the invention maybe obtained in various ways. For example, there may be employed an aqueous solution only containing the"5i6 dihydroxy-indo1e, with the exclusion of as trace impurities. The sequestering agent may be, for

2,934,396 Patented Apr. 26, 1960.

any other reactant, the pH-vaiue of such a solution being of course slightly acid. It is also possible to acidity this aqueous solution more or less strongly, for example by means of an inorganc acid, an organic acid, e.g. formic, acetic or monochloroacetic acid, or any compound containing at least one acid hydrogen atom.

The concentration of 5:6-dihydroxy-indole in the solution as applied to the hair or other material may vary within fairly wide limits. Generally it will be between 0.1% and 10% and preferably between 1% and 2% by weight of the solution. The term aqueous solution as employed here means any solution the principal solvent. of which is water. It is of course possible, without departing from the scope of the invention, to use inthe preparation of such a solution Water alone or in admixture with water-rniscilzrle solvents, notably mixtures of,

medium than in alkaline medium and it is possible-to haveit prepared in advance in the form of any aqueous solu-' tion and, whenever desired, further to improve the stability of such a solution by adding thereto a small amountof a reducing agent, such as, for example, an alkali metal sulphite, bisulphite or hydrosulphite, this addition prefer ably being made first, i.e. before the 5:6-dihydroxy-indole is added. According to the present invention, the stability of aqueous solutions of 5:6-dihydroxy-indole may also be enhanced by adding thereto a small quantity, preferably 0.2% to 0.5%, of a sequestering agent, i.e. a compound capable of forming complexes with ions of alkadne-earth metals or of heavy metals, often existing example, ethylenediaminc-tetracetic acid or one of its salts, such as that known under the trade mark Trilon B.

When the aqueous 5:6-dihydroxy-indole solution has been in contact with the hair or other material for a period of 5 to 60 minutes the excess solution is blotted oif, for example by pressing the hair in a towel.

The shade is then developed in situ by applying to the hair or other material an aqueous solution capable of inducing oxidation and/orpolymerization of the 5:6-di-" hydroxy-indole. s

The choice of this oxidizing agent, as also the lengthof time during which it should be maintained in contact with the hair or the material to be dyed, depends to some extent upon the final shade which it is desired to obtain.

It is also possible to act upon the final shade by adjustingthe pH of the developing solution to a preselected value, e.g. by including acid or alkaline materials therein.

In one method of carrying out the process of the inven-- tion there is used as oxidizing agent the oxygen of theambient air, if desired ozonized. In such an embodiment the development of the shade, which amounts to the rapid fixing of the atmospheric oxygen bythe hair or similar material impregnated with 5:6-dihyclroxy-indole, is effected by applying in a second step as" a developing medium an aqueous solution containing an alkalizing agent consisting preferably of ammonia, a basic ammo nium salt such as ammonium carbonate or triamrnoniumcontact with the hair or similar material for 10 to 60 minutes as necessary for the penetration of the reactants. The hair is then rinsed clear with water and dried. The development of the shade, which is initiated by the alkalization, may proceed for some time, this process thenconstituting a progressive dyeing process.

In a second method of carrying out the invention, there is applied in a second step, for the development of the shade, an aqueous solution of an oxidizing agent such as, for example, hydrogen peroxide, or an alkali metal or ammonium iodate, periodate or persulphate or an alkali metal salt of an N-chlorinated derivative of a sulphonamide. This soluiton is allowed to act for a period of time sufficient for the development of the shade, generally from 5 to 20 minutes, and the hair is then rinsed, shampooed, rinsed again and dried. The pH of this aqueous oxidizing solution, applied in the second place, may be adjusted to any desired value, either acid, neutral or alkaline, by the addition of any appropriate reactant, for example an inorganic or organic acid, a salt having an acid reaction, a buffer, a salt having a basic reaction or a base such as ammonia or an organic amine. The choice of the most suitable value depends mainly, but not solely, upon thenature of the oxidizing agent employed. It the latter is hydrogen peroxide, an alkali metal or ammonium iodate or periodate or an alkali metal salt of an N-chlorinated derivative of a sulphonamide, it is generally preferable to operate in a basic medium, whereas the operation is preferably carried out in an acid medium if the oxidizing agent is an alkali metal or ammonium persulphate. However, if the oxidizing agent employed is an iodate or a periodate, it is preferable not to operate at a pH-value lower than 3 and to avoid the use of a strong inorganic acid for adjusting the pH to the desired value.

Whatever the pH chosen for the development of the shade, the concentration of the oxidizing agent in the aqueous solution may be chosen between fairly wide limits, depending upon the desired shade and upon the own solubility of the specific oxidizing agent which is to be used. Generally speaking, the quantity of oxidizing agent to be employed corresponds to 0.5 to g. per 100 cc. of solution, the volume of oxidizing solution to be employed being substantially the same as the quantity of dihydroxyindole solution.

When the oxidizing solution employed in the second step is acid or neutral, i.e. free from ammonia and organic amines, it is probable that the pigment formed results from the formation of the quinone corresponding to 5,6-dihydroxyindole. However analytical data has shown that if the oxidizing solutions are rendered alkaline by means of ammonia or an amine, the molecule of the pigment obtained contains nitrogen issuing from the ammonia or the amine employed. The same holds true when the oxidation is effected through the intermediary of ambient air and in the presence of ammonia or an amine, according to the first embodiment of the invention.

According to an accesory feature of the invention and whatever the specific embodiment to be dealt with, there can be advantageously added to the developing solution a quantity of a neutral, strongly ionized inexpensive electrolyte such as, for example, sodium chloride or sodium sulphate.

The dyeing process according to the invention may be carried out, not only by means of aqueous solutions as referred to above, but also by means of creams, pastes or jellies, the adjustment to the required consistency being efiected by any method usual in hair dyeing.

The use of 5,6-dihydroxy-indole, under the abovedefined conditions, constituting the object of the present invention may be combined with that of dior triphenols capable of dyeing hair and other keratinous fibres at room temperature under analogous conditions such as those defined, for example, in our applications Nos. 709,479 and 709,602, both filed January 17, 1958.

The following examples will serve to illustrate the invention:

Example I illustrates the case where the development is effected in a basic medium and by oxidation in the ambient air, while the other examples illustrate cases where the development is effected by means of an oxidizing solution.

Example I An impregnating solution having the following composition is prepared:

5,6-dihydroxy-indole g l Acetic acid cc 5 Water to make cc.

Naturally white or nearly white live hair is impregnated with this solution. After contact for 20 minutes, the excess solution is blotted off, for example by means of a towel, and an aqueous solution having the following composition is then applied:

Sodium chloride g- 4 Water cc 100 20% ammonia cc 17 After contact for 20 minutes, the hair is rinsed clear with water and dried. The hair is dyed a dark grey which gradually changes to black. (This constitutes a progressive dyeing.)

Example II An impregnating solution as set forth in Example I is applied to naturally white live hair.

This solution is left in contact with the hair for 20 minutes, then blotted off, and the following solution is then applied:

Sodium chloride g-.. 4 Hydrogen peroxide (20 vol.) (6% of H O cc 2.5 Water to make 100 cc.

This solution is left in contact with the hair for 1 hour, and the hair is then rinsed, shampooed, rinsed again and dried. A light grey shade is obtained, which remains substantially unchanged in the following weeks.

Example III Sodium chloride g 4 Water 100 20% ammonia cc 17 Hydrogen peroxide (20 vol.) (6% of H 0 cc 0.3

This second solution isleft in contact with the hair for 30 minutes, and the hair is then rinsed, shampooed, rinsed again and dried. The hair is dyed jet-black.

Example IV Almost white live hair is impregnated with an impregnating solution as set forth in Example I.

After contact for 20 minutes, the excess solution is blottedoff and the following solution is then applied:

Sodium chloride g 4 Monomethylamine (in 33% aqueous solution) ..cc 10 Hydrogen peroxide (20 vol.) (6% of H 0 cc 2.5 Water to make 100 cc.

This solution is left in contact with the hair for 20 minutes, and the hair is then rinsed, shampooed, rinsed again and dried. The hair is dyed medium ash-blond.

Example V Nearly white live hair is impregnated with an impregnating solution as defined in Example I. After a period of contact of 20, minutes, the excess solution is blotted deep black.

off and an aqueous solution having the followingcomposition is applied! I Sodium chloride I! 20% ammonia p v M 6 Hydrogen peroxide (20 vol.) (6% of H O cc 23 Water to make 100 cc.

After contactfor 20 minutes, the hair is rinsed, shampooed, rinsed again and dried. A medium brown shade is obtained.

Example VI Naturally white or nearly white hair is impregnated with an impregnating solution as defined in Example I.

.Thesolution is left in contact for 20 minutes, whereafter the excess solution is blotted off and an aqueous solution having the following composition is applied:

Sodium chloride g 3.2 20% ammonia cc 2 Hydrogen peroxide (20 vol.) (6% of H ..cc 16 Water to make 100 cc. 1

This solution is left in contact with the hair for 20 minutes, the hair is then rinsed, shampooed, rinsed again and dried. A light brown shade is obtained.

, Example VII Naturally white live hair is treated with an impregnating solution as defined in Example I.

This solution is left in contact with the hair for 30 minutes, whereafter the excess solution is blotted off and an aqueous solution having the following composition is applied to the hair.

Sodium chloride g 5 Triethanolamine c" 26 Hydrogen peroxide (20 vol.) (6% of H 0 cc 10 Water no 75 After contact for 30 minutes, rinsing, shampooing, rinsing again and drying, the hair is dyed grey.

Example VIII Almost white live hair is impregnated with an impregnating solution as defined in Example I, which is left in contact therewith for 20 minutes. After blotting off the excess solution, the following solution is applied:

Sodium chloride g 4.2

Chloramine T (sodium N-chloro-p-toluene-sulphonamide) g 1.2

20% ammonia cc 14 Water to make 100 cc.

After contact for 20 minutes, the hair is rinsed, shampooed, rinsed again and dried. The hair is dyed a fine Example IX Naturally white live hair is impregnated with the following impregnating solution: 5,6-dihydroxy-indole g 1 Acetic acid cc 0.5 Water to make 100 cc.

The pH-value of this solution is 3.3. This solution is left in contact with the hair for 15 minutes. The excess solution is then blotted off and an aqueous 4% sodium iodate solution is then applied to hair. After 15 minutes, the hair is rinsed, shampooed, rinsed again and dried. A dark grey shade is obtained.

Example X A solution having the following composition is prepared:

5,6-dihydroxy-indole g 1 Water cc .100

The pH-value of such a solution is 6.2. This solution.

is applied to naturally white live hair and left in contact therewith for 15 minutes. After blotting off the excess solution, an aqueous 4% sodium iodate solution is applied to the hair. After this solution has been allowed to act for 15 minutes, the hair is rinsed, shampooed, rinsed again and dried. The hair is dyed a dark grey, which is not, however, as dark as the shade obtained in Example IX.

Example XI Naturally white live hair is treated with an impregnating solution as defined in Example IX.

After contact for 15 minutm, the excess solution is blotted off and an aqueous 4% sodium periodate solution is then applied to the hair. After contact for 15 minutes, rinsing, shampooing, rinsing again and drying,

the hair is dyed in a greyshade which is a little lighter than that obtained in Example X.

Example XII A solution having the following composition is prepared: 5,6-dihydroxy-indole g.. 1 Water cc solution is applied thereto. After 15 minutes, the hair is rinsed, shampooed, rinsed again and dried. A medium grey is obtained.

Example XIV An aqueous solution containing 1% by weight of 5,6- dihydroxy-indole is applied to naturally white live hair. This solution is left in contact with the hair for 15 minutes. The excess solution is then blotted off and an aqueous 5% sodium persulphate solution is applied. After 15 minutes, the hair is rinsed, shampooed, rinsed again and dried. The shade obtained is medium grey.

Example XV Naturally white live hair is impregnated with an impregnating solution as defined in Example I.

When this solution has been allowed to act for 20 minutes, the excess solution is blotted off and a solution having the following composition is applied:

20% ammonia cc 15 Sodium iodate g.. 0.5 Water to make 100 cc.

After contact for 20 minutes, the hair is rinsed, shampooed, rinsed again anddried. There is obtained a very dark grey shade having a violet tinge, gradually changing to black.

Example XVI Almost white live hair is impregnated with an impregnating solution as defined in Example I which is left incontact therewith for 20 minutes. The excess solution is then blotted 0E and a solution having the following composition is applied thereto:

Sodium periodate ....g.. 0.5 20% ammonia ..cc-.. 15 Water to make 100 cc.

This solution is allowed to act for 20 minutes and the hair is then rinsed, shampooed, rinsed again, and dried. There is directly obtained a fine black shade, which is substantially permanent.

Example XVII,

pregnating solution as defined in Example I.

After contact for 20 minutes, the excess liquid is blotted'ofl and a solution having the following composition is applied to the hair:

Ammonium persulphate g 0.5 20% ammonia cc 15 Water to make 100 cc.

This solution is left in contact with the hair for 20 minutes. drying, the hair is dyed a fine deep black.

Example XVIII A solution having the following composition is employed to impregnate almost white live hair:

5,6-dihydroxy-indole g 1 Monochloroacetic acid g 1 Water to make 100 cc.

After contact for 20 minutes with the hair, the excess liquid is blotted ofi and a solution having the following composition is applied:

Ammonium persulphate g 6 Sodium chloride g 4 Monochloroacetic acid g 3 Water to make 100 cc.

After rinsing, shampooing, rinsing again and Whatwe 'claimzisz 1. A process for dyeing live human hair -'and;keratinous fibers at room temperature by means of 5,6-dihydroxyindole which comprises impregnating said materials in a first step with an aqueous solution of said dihydroxyindole adjusted to a pH value of less than 7 and, after having allowed impregnation to proceed for 5 to 60 minutes and having blotted off the excess solution, applying in a second step onto the impregnated material an aqueous solution containing a. nitrogenous base selected from the roup consisting of ammonia, basic ammonium salts and organic amines and further containing an oxidizing agent selectedrfr'om the group consisting of hydrogen peroxide, alkali metal and ammonium bromates, iodates, periodates, perborates and persulphates and alkali metal salts of N-chlorinated ,sulphonamides.

2. A process for dyeing live human hairandlkeratinous fibers at room temperature by means of 5,6-dihydr0xyindole which comprises impregnating said materials .in a first step with an aqueous solution containing from 0.1% to 10% by weight of 5,6dihydroxyindole and adjusted to a pH-value of less than 7 and, after having allowed impregnation to proceed for 5 to 60 minutes and blotted ofi the excess solution, applying in a second step onto the impregnated material an aqueous solution containing a nitrogenous base selected from the group consisting of ammonia, basic ammonium salts and organic amines and further containing an oxidizing agent selected from the group consisting of hydrogen peroxide, alkali metal and ammonium bromates, iodates, periodates, perborates and persulphates and alkali metal salts of IN-chlorinated sulphonamides.

References Cited in the file of this patent UNITED STATES PATENTS 1,133,594 Monsavon Nov. 19, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF "CORRECTION Patent No. 2,934,396 April 26., 1960 Roger Charle et a1.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 8, line 35., list of References Cited-,- strike out "UNITED STATES PATENTS and insert instead FOREIGN PATENT line 36,. strike out Monsavon and insert instead France Signed and sealed this 25th day of October 1960.

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents 

1. A PROCESS FOR DYEING LIVE HUMAN HAIR AND KERATINOUS FIBERS AT ROOM TEMPERATURE BY MEANS OF 5,6-DIHYDROXYINDOLE WHICH COMPRISES IMPREGNATING SAID MATERIALS IN A FIRST STEP WITH AN AQUEOUS SOLUTION OF SAID DIHYDROXYINDOLE ADJUSTED TO A PH VALUE OF LESS THAN 7 AND, AFTER HAVING ALLOWED IMPREGNATION TO PROCEED FOR 5 TO 60 MINUTES AND HAVING BLOTTED OFF THE EXCESS SOLUTION, APPLYING IN A SECOND STEP ONTO THE IMPREGNATED MATERIAL AN AQUEOUS SOLUTION CONTAINING A NITROGENOUS BASE SELECTED FROM THE GROUP CONSISTING OF AMMONIA, BASIC AMMONIUM SALTS AND ORGANIC AMINES AND FURTHER CONTAINING AN OXIDIZING AGENT SELECTED FROM THE GROUP CONSISTING OF HYDROGEN PEROXIDE, ALKALI METAL AND AMMONIUM BROMATES, IODATES, PERIODATES, PERBORATES AND PERSULPHATES AND ALKALI METAL SALTS OF N-CHLORINATED SULPHONAMIDES. 